Storage and deaeration of viscous liquid material



Dec. 27, 1960 A CERWNKA 2,966,230

STORAGE AND DEAERAHON oF vIscoUs LIQUID MATERIAL Filed spt. 15, 1958 l lIl |||I JSM' Ill mh, l I I United States Patent Otice 2,966,230 PatentedDec. 27, 1960 STORAGE AND DEAERATION F VISCOUS LIQUID IWATERIAL AnthonyCervinka, Batawa, Dutario, Canada, assigner 21:) Bata Shoe Company ofCanada Limited, Ontario,

anada Filed Sept. 15, 1958, Ser. No. 761,088

Claims priority, application Canada Jan. 17, 1958 2 Claims. (Cl. 18S-2.5)

This invention relates to the storage and deaeration of viscous liquidmaterial.

ln the moulding of articles, air bubbles are usually un desirable in theliquid moulding material. This is especially true in slush mouldingprocesses, where thinwalled articles are being moulded and the presenceof air bubbles in the liquid moulding material will tend to weaken ordestroy the usefulness of the finished product. For example, in themanufacture of footwear by slush moulding, small air pockets in theuppers or soles will greatly weaken the finished boot or shoe.

.To overcome this problem it has been proposed in the past to use highvacuum force to eliminate such bubbles. The present invention relates toa new and simpler method of disposing of unwanted air bubbles inliquids, using a system of batlles, together with a relatively lowvacuum force.

The attached drawing illustrates one embodiment of an apparatus suitablefor use with the invention.

Referring now in detail to the drawing, a storage tank 1 and a pressurefilling -tank 2 are illustrated together with a supply tank feed-pipe 3leading to the storage tank 1 from a mixing vat (not shown). The supplyof moulding liquid is fed through the supply pipe 3 into the storagetank 1, and the supply fed into the storage tank 1 can be controlled byany known means.

A draining area is shown near the upper limit of the storage tank 1, andthis is provided with a screen closure 5. 'lhis draining area 4 isdesigned for use with slush moulding processes, and is positioned toreceive the moulding liquid as the moulds are emptied of mouldingmaterial following initial heating and gelling of a skin within themould. The liquid material being emptied over the draining area ilows inthe direction of the arrow 6 through the screen 5 and over the bailletables 7, respectively, in the direction of arrows 8 and 9. The liquidmaterial is then fed under and over a series of vertical baffles. In thedrawing light bailles are shown, and are numbered 10 to 17. As themoulding liquid fills the compartment on the outside of baille 10, thebaille opening at the bottom of baille 10 permits the liquid in thecompartments on each side of baille 10 to attain a common level.

As the level of the liquid in the iirst two compartments reaches thelevel of baille 11 the liquid will ow over baille 11 and till thecompartments on each side of baille 12. Similarly, as the quantity ofliquid in the storage tanks increases, the compartments on each side ofbaille 13 will become lled.

As the liquid flows through the baille compartments, gravitational forcecauses the air bubbles entrapped in the liquid to the surface. As theliquid ows over the top of bailles 11 and 13 the bubbles are liberatedfrom the moulding liquid. The bubbles thus liberated will remain on thesurface of the liquid in the compartments behind bailles 13 and 11, andwill not continue with the ow of liquid beyond baille 13.

Turning now to the pressure illling tank 2, it will be seen that thistank is filled from the storage tank 1 by means of a pump 18. The pump18 sucks the liquid from compartment 19, tending to create la Vacuumabove the liquid level. The vacuum created in the upper part ofcompartment 19 causes the level of the liquid in compartment 20 to rise,and the level of the liquid in column 21 to fall, thus creating a lowvacuum in column 21. Due to the low vacuum in column 21, atmosphericpressure on the compartments on either side of baille 15 will cause theliquid to rise in column 22, and eventually to ilow over baille 15. As4the liquid ilows over the baille 15 the pressure in the air bubbleswill be greater than that of the surrounding medium, liberating thebubbles from the liquid. A permanent low Vacuum will remain in Vacuumbell 26.

It may be useful to supplement the vacuum-causing action of the pump 18with an auxiliary vacuum pump 23 on vacuum bell 26.

Thus, a continuous supply of deaerated moulding liquid can be keptavailable in the pressure ylling tank 2, being fed to through pipe 24from pump 18 to pressure filling tank 22 as required. Leading from thepressure iilling tank 2 is a pipe 25, connecting with -a mould illingstation (not shown). As mentioned above, the level of the liquid in thestorage tank 1 can be controlled by any known means which will actuatethe entry of an additional supply of liquid through the supply tank feedpipe 3, as the supply becomes depleted through use.

While one preferred embodiment is herein described, the spirit and scopeof the invention should be limited only by the appended claims.

I claim:

l. An apparatus for the storage and deaeration of viscous liquidmaterial comprising end, side, top and bottom walls deiining a storagetank, means for introducing liquid material into said tank through oneof said side Walls, a screened inlet in the top wall adjacent one ofsaid end walls for admitting further liquid into the storage tank, atleast one baille table within the tank below said inlet inclineddownwardly from adjacent said one end wall in the direction of theopposite end wall, at least a second baille table below saidfirst-mentioned baille table inclined downwardly in the direction of andterminating short of said one end wall to provide a circuitous path forIthe further liquid, a plurality of spaced apart vertical baiilesextending longitudinally of the tank for a substantial length of thetank with at least the vertical baille adjacent said one end wall beingconnected to said second baflle table to provide a compartment betweensuch vertical baille and said one end wall and said succeeding baillesdefining therebetween a series of compartments, means providing liquidcommunication between said succeeding compartments, at least two of saidvertical batlles between the screen inlet and the other end wall beingextended above the top wall of the tank to constitute an elevatedcompartment, -a vacuum bell positioned on top of said elevatedcompartment, means dividing said elevated compartment into two verticalcolumns, a pressure lling tank, pump means Within said storage tankbetween said opposite end wall and the last vertical bafle communicatingwith said pressure filling tank whereby when said pump means aspiratesliquid from the space between said opposite end Wall and said last-namedvertical baffle there is created -a vacuum above the liquid levelthereby causing the liquid level of the column in said elevatedcompartment closest to said pump means to fall and cause the liquidlevel in the other of said columns to rise and ultimately iow over thevertical bae separating such columns thus liberating bubbles from theliquid.

2. An apparatus as claimed in claim l, further including an auxiliaryvacuum pump operably connected with said vacuum bell.

References Cited in the iile of this patent UNITED STATES PATENTS

